22LR Ammo Issues

[Eoddave27]

Hey guys, I’ve been having some ammo issues and wanted to see if anyone else has had the same thing happen. Life got really busy and I haven’t been able to shoot matches consistently for probably the last year and a half. Things finally slowed down so I dusted my rifle off and finally have been able to shoot again. I have a case of SK Semi Auto that I used for practice ammo. It pretty much always had the same velocity as SK Rifle Match but it just wasn’t as consistent. I loaded some up and as soon as I started shooting it I noticed something was way off. When I chronographed it I was getting crazy low velocities. When I say low I mean 800-900 FPS at 50-60 degree temps. Every once in awhile I will get one that is over 1000 FPS but that is rare. Everything else I have is in the 1080-1100 FPS which is normal in my rifle. I have tried the ammo in a Tikka, CZ and my Vudoo and it shoots the same in all three rifles. It’s stored in a climate controlled room that stays around 70 degrees year round with all my other ammo. No crazy humidity swings either. I’m just scratching my head trying to figure out what is going on. I bought the ammo probably 2-2 1/2 years ago so it isn’t 20 or 30 years old and stored in a garage. Has anyone else seen this happen? I’m hoping when it gets hot the velocity will come back up so I can at least use it for practice ammo.

 

[Emerson0311]

Hey guys, I’ve been having some ammo issues and wanted to see if anyone else has had the same thing happen. Life got really busy and I haven’t been able to shoot matches consistently for probably the last year and a half. Things finally slowed down so I dusted my rifle off and finally have been able to shoot again. I have a case of SK Semi Auto that I used for practice ammo. It pretty much always had the same velocity as SK Rifle Match but it just wasn’t as consistent. I loaded some up and as soon as I started shooting it I noticed something was way off. When I chronographed it I was getting crazy low velocities. When I say low I mean 800-900 FPS at 50-60 degree temps. Every once in awhile I will get one that is over 1000 FPS but that is rare. Everything else I have is in the 1080-1100 FPS which is normal in my rifle. I have tried the ammo in a Tikka, CZ and my Vudoo and it shoots the same in all three rifles. It’s stored in a climate controlled room that stays around 70 degrees year round with all my other ammo. No crazy humidity swings either. I’m just scratching my head trying to figure out what is going on. I bought the ammo probably 2-2 1/2 years ago so it isn’t 20 or 30 years old and stored in a garage. Has anyone else seen this happen? I’m hoping when it gets hot the velocity will come back up so I can at least use it for practice ammo.

My SK seemed particularly sensitive to temp and humidity, compared to Eley options. Cooler temps would be down around 1000fps. Also a lot of high/low flyers. I have several bricks I don’t even trust as practice ammo anymore.

If your live where it gets quite hot for most of the summer, your SK should do a lot better in the heat. Mine was 1050-ish. SKLRM was almost 1070.

 

[6.5SH]

SK Semi-Auto should have been faster from the start, perhaps had a bad lot.

SK Ballistic table | .22lr ammunition | rimfire ammo | Smallbore

The SK Ballistic table includes all available ballistic data for SK rimfire ammo. BC coefficients can be found in the lower left corner.

sk-ammunition.com

Can take SK's chart with a grain of salt as there are three nominal velocity ranges;
1073 fps (Rifle Match, Pistol Match, Standard Plus, Magazine)
~1100 fps (Pistol Match Special, Biathlon Sport, Semi-Auto Rifle, Long Range Match)
1263 fps (High Velocity Match)

FWIW I did experience a 2+ year old brick of SK Standard Plus that slowed down, but talking 1080 down to 1030 average, multiple shots in the string were below 1020. That particular batch never did shoot as good as prior purchases, but wasn't that much apparent slowness when I first tested it.

I've had one lot of Semi-Auto that shot great (like good enough for ARA use), the next lot is barely tolerable for Silhouette Benchrest. Can shoot a 40x but a shoot-off with chickens at 100 meters is matter of luck and not having a round go faster.

 

[Eoddave27]

SK Semi-Auto should have been faster from the start, perhaps had a bad lot.

SK Ballistic table | .22lr ammunition | rimfire ammo | Smallbore

The SK Ballistic table includes all available ballistic data for SK rimfire ammo. BC coefficients can be found in the lower left corner.

sk-ammunition.com

Can take SK's chart with a grain of salt as there are three nominal velocity ranges;
1073 fps (Rifle Match, Pistol Match, Standard Plus, Magazine)
~1100 fps (Pistol Match Special, Biathlon Sport, Semi-Auto Rifle, Long Range Match)
1263 fps (High Velocity Match)

FWIW I did experience a 2+ year old brick of SK Standard Plus that slowed down, but talking 1080 down to 1030 average, multiple shots in the string were below 1020. That particular batch never did shoot as good as prior purchases, but wasn't that much apparent slowness when I first tested it.

I've had one lot of Semi-Auto that shot great (like good enough for ARA use), the next lot is barely tolerable for Silhouette Benchrest. Can shoot a 40x but a shoot-off with chickens at 100 meters is matter of luck and not having a round go faster.

The first several bricks I bought I had planned to use in my son’s 10/22 but it shot amazing and I ended up shooting in in my Vudoo and actually won a match with it. It averaged around 1120 FPS. The next two two cases I bought were still around 1120 but were not consistent enough to trust at a Match so it was used as training ammo. The ammo I have that averages around 850 FPS are the same lots that shot 1120 fps the last time I shot it. I’m thinking about getting the ammo up to around 95 degrees and see if velocity comes back up. I would hate to have nearly 2 cases if ammo that are basically trash.

 

[littlepod]

The first several bricks I bought I had planned to use in my son’s 10/22 but it shot amazing and I ended up shooting in in my Vudoo and actually won a match with it. It averaged around 1120 FPS. The next two two cases I bought were still around 1120 but were not consistent enough to trust at a Match so it was used as training ammo. The ammo I have that averages around 850 FPS are the same lots that shot 1120 fps the last time I shot it. I’m thinking about getting the ammo up to around 95 degrees and see if velocity comes back up. I would hate to have nearly 2 cases if ammo that are basically trash.

That's crazy. I've never experienced that. I know I have lots of center-x sitting in my closet that are 3 yrs old and still shoot the same.

If it a fresh new lot, then sure maybe a bad lot, but the fact that it used to shoot, and then suddenly not shoot out of the same gun is crazy.

You verify the chrono isn't having issues measuring past 1120 for some weird reason?

 

[6.5SH]

One thing just struck me about how I store my ammo, anything with individual boxes in a brick in particular.

I'm sure we all store a 50 count box with the bullet down. Eley has shrink-wrapped bricks so is easy to visualize what is bullet down; vertical.
SK bricks? They open horizontally, so out of habit I tend to have them horizontal which means the boxes inside are not bullet down.

There is a recent change with Lapua, the bricks are longer like a gold bar to orient the individual boxes bullet down when horizontal...

Is lube migration into the powder charge over time the culprit here?

 

[Eoddave27]

One thing just struck me about how I store my ammo, anything with individual boxes in a brick in particular.

I'm sure we all store a 50 count box with the bullet down. Eley has shrink-wrapped bricks so is easy to visualize what is bullet down; vertical.
SK bricks? They open horizontally, so out of habit I tend to have them horizontal which means the boxes inside are not bullet down.

There is a recent change with Lapua, the bricks are longer like a gold bar to orient the individual boxes bullet down when horizontal...

Is lube migration into the powder charge over time the culprit here?

You know, that’s something I never thought about. The powder could be settling away from the primer and causing a slower velocity. I’m not sure if all the ammo that is shooting slow has been from loose boxes stored out of the brick bullet down but I will make a point to check some of the ammo that is out of a fresh brick and see if I have issues with it. It seems like a likely cause however. I will get to the range a let everyone know.

Littlepod the chronograph is good. Every other ammo I checked at the same outing has chronographed exactly where it should. I suspect it’s the storage orientation. I’m pretty sure the boxes I tried were loose boxes not stored in brick form with the bullet orientation pointing down.

 

[littlepod]

That is very interesting thought. I wonder if I need to start storing ammo in my pack with the bullet down configuration too... Right now it's in something like this https://hozandshield.com/shop/ols/products/200-rnd-ammo-box but stored horizontally in my pack. Though I am guessing this must take quite a long period of time in this configuration to cause harm.

 

[Eoddave27]

It did make me wonder if I shake the heck out of my ammo before I shoot it if I will get more consistent SD and ES numbers. It makes sense. I don’t know if you guys reload centerfire but inconsistent ignition causes all kinds of issues. If all my powder has settled in the ammo away from the primer it would cause a very inconsistent ignition and most likely a loss in velocity. The vast majority of people are not testing their ammo with a chronograph and would never even know it was shooting 200-300 fps slower. At 50-60 yards there would be a noticeable POI change but if you are just shooting beer cans in the back yard you just aim a little higher.

 

[littlepod]

I found this thread and asked here - https://www.snipershide.com/shootin...ith-lot-tested-center-x.7236541/post-12108087